This invention relates generally to methods and systems for establishing and conducting communications between nodes in a network. More particularly, the present invention relates to establishing communications between nodes in a network using predetermined time periods for communications between the nodes and directional pointing of the antenna of each node.
Communications between mobile network nodes have been accomplished using directional antennae, which offer the advantages of higher data rate and longer range than omnidirectional antennae. However, directional antennae alone cannot be used for communications between nodes whose locations are unknown to each other. Therefore, in prior art, directional antennae alone cannot be used to establish communication between nodes, because the location of each node is unknown to the other until both nodes join a common network. Using only directional antennae to establish communications is unreliable because a transmitting network node may not be pointing at a receiving network node when the receiving network node is pointing at the transmitting network node. Thus, an omni-directional antenna is also utilized in prior art to establish temporary, low-rate communications to determine where other nodes reside. After a first node obtains the location of at least one other node that belongs to a network the first node wishes to join, the first node can point its directional antenna towards the other node to establish high-rate, long-range communications. However, using the omni-directional antenna to establish the location of other nodes in the network requires additional spectrum space and power to compensate for the operation of the omni-directional antenna. More specifically, the omni-directional antenna requires additional power for operation as it is not focused in a particular direction. Further, the omnidirectional antenna imposes cost and weight on the node beyond the cost and weight of the directional antennae.
Thus, communicating between network nodes using an omni-directional antenna and a directional antenna is costly because two antennae are required for each network node, one antenna (omni-directional) to establish location and another antenna for directional communication. Additionally, the omni-directional antenna utilizes extra spectrum width as well as additional power to transmit data over long distances.
In view of the foregoing, there is a need for more efficient methods and systems for establishing and conducting communications within a network. Furthermore, there is a need for establishing and conducting communications within a network which utilizes a single antenna for establishing location and conducting communications, wherein the antenna utilizes a more narrow spectrum for communications, and utilizes less power in the transmission and reception of data.